Current, rollover stability control (RSC) schemes address vehicle roll and include a variety of sensors sensing vehicle dynamic conditions. RSC systems further include a controller controlling a distributed brake pressure for reducing a tire moment such that the net moment of the vehicle is counter to the vehicle roll direction.
The RSC sensors include a speed sensor, a lateral acceleration sensor, a roll rate sensor, and a yaw rate sensor. The roll rate sensor is typically utilized to estimate the roll angle and to calculate the desired control pressure. Fault modes of the roll rate sensor, therefore, may cause unintended braking, reduced performance or even loss of stability. Such fault modes must be rapidly diagnosed and indicated so that the RSC system is shut down.
U.S. Pat. No. 6,315,373 addresses a similar issue of fault detection for a roll control device. It, however, merely addresses the detection of a lateral accelerometer in a system that uses lateral acceleration signals to detect vehicle roll over stability, which is insufficient for a comprehensive RSC system. Furthermore, this method relies heavily on the vehicle suspension model. Variations of the suspension parameters, such as the spring stiffness and damping ratio, may cause an unnecessary false warning (i.e. false positive) or a missed detection (i.e. false negative).
It is therefore desirable to provide a system that rapidly detects a roll rate sensor fault in a rollover stability control system that can be applied to various vehicle platforms without tuning. This method should also be able to detect a fault independent of the specific fault modes as well as detect a fault that is otherwise not detectable by checking electrical specifications.